Film bag and method for producing it

ABSTRACT

The invention relates to a film bag with two front faces ( 1, 1′ ), side folds ( 2 ) which are inserted between the front faces in a V-shaped manner, and a resealable closure ( 3 ) in a top opening in the bag, comprising two profiled strips ( 4, 4′ ) and a slide ( 5 ). The film layers of the bag which rest one on the other are connected to transverse and longitudinal sealed seams at the bottom and along the edges of the side folds ( 2 ), with the longitudinal sealed seams ( 6 ) which run along the side folds extending from the bottom to the upper edge ( 7 ) of the bag. The resealable closure ( 3 ), including its slide ( 5 ), is arranged at a distance from the upper bag edge ( 7 ) inside the bag. At least one front face ( 1′ ) of the bag contains a punched-out area ( 8 ) for the slide ( 5 ) which is matched to the dimensions of the slide ( 5 ) and in which the slide ( 5 ) is positioned before the bag is used for the first time. The invention also relates to a method for producing the described film bag.

The invention relates to a film bag with

-   -   two front faces,    -   side folds inserted between the front faces in a V-shaped        manner, and    -   a resealable closure in a top opening of the bag comprising two        profiled strips and a slide joining the profiled strips,        wherein one of the profiled strips is connected to a front face        and the other profiled strip after a filling of the bag can be        connected to the other front face, wherein the film layers of        the bag which rest one on the other of the bag are connected to        transverse and longitudinal sealed seams at the bottom and along        the edges of the side folds and wherein the longitudinal sealed        seams which run along the side folds extend from the bottom to        the upper edge of the bag. The film bag which lies flat at first        is filled with the filling material in bag filling facilities.        The filling takes place at the top of the bag. The filling        material is introduced in an opening which is still present        between the resealable closure and a front face of the film bag.        Subsequently, this opening is sealed by a sealed seam. Film bags        with the described features are used, among others, for the        packaging of animal feed.

A film bag with the described features is known from DE 202 07 333 U1.The slide of the resealable closure overlaps the seal edges rider-likeand projects at the top side of the bag. The profile strips areconnected to each other at their end facing the slide and form anoriginality seal which can be torn open at the first use of the filmbag. Disadvantageous is that from the outside it is not clear whetherthe originality seal is still undamaged. Furthermore, there is a dangerthat the projecting slide catches on obstacles during transport of thebag and during handling in the trade and thereby moves unchecked. Theproduction of the film bag is also complicated. Following the bagmanufacture, resealable closures are applied in a downstream facility.For this purpose a film section of the film bag already manufactured isopened at the top section of the bag, a resealable closure is placed onthe film sheet lying underneath and connected to it. Subsequently, theopened film section is folded back and the sealed seams which are stillmissing are applied. For the application of the resealable closuresexisting equipment for the manufacture of film bags have to be enlargedby an additional facility for applying the resealable closures. Theadditional facility for applying the resealablle closures is complicatedand requires considerable space. In this respect there is also a need tointegrate the application of resealable closures in the usual bagmanufacturing method.

Against this background the object of the invention is to provide a filmbag having a slide closure which is arranged covered and which is simpleto manufacture. Further, a method is provided in which the applicationof the resealable closure is carried out during the continuous forwardrun of a planar film web before the manufacture of the bag.

Departing from a film bag with the features described in the above, theobject of the invention is solved in that the resealable closureincluding its slide are arranged at a distance to the upper bag edgeinside the bag and that at least one front face of the bag contains apunched-out area for the slide which is matched to the dimension of theslide in which the slide is positioned before the bag is used for thefirst time. According to the invention, the resealable closure which isarranged in the top opening of the film bag covered wherein the slideremains visible through the slide. For the consumer it is immediatelyrecognizable from the outside that the bag is provided with a slideclosure and the slide closure is properly closed. Furthermore, the slidepunch-out fulfils an important function in the manufacture of thee filmbag. The slide punch-out which is matched to the dimension of the slideand encloses it, enables an application of the resealable closure on aplanar film web before the latter runs through folding stations in whichthe film web is folded and the side folds are formed. The slidepunch-out sits exactly at the position of the slide and prevents ashifting of the resealable closure during the web run over guiding traysof the folding stations against the direction of movement of the film.

The front sides of the film bag have a strip-shaped section which coversthe resealable closure at the upper end of the bag which can be torn offin accordance with a preferred embodiment of the invention along aperforation line arranged approximately at the level of the slide orunderneath the slide. Punching lines extending through the longitudinalsealed seams up to the outer edges of the bag suitably join at the endsof the perforation line. The strip can be completely removed as a wastestrip in a simple way from the film bag in the embodiment described whena film bag is used for the first time. In order to facilitate thedetachment of the strip, it is advantageous to have the side fold endunderneath the perforation line.

The waste strip, which can be torn off along the perforation line, canalso fulfil the function of an originality seal when the double-layeredstrip is sealed at its upper edge with a transverse sealed seam afterthe filling of the film bag. At the first use of the film bag, the upperside strip has to be detached in which the resealable closure is exposedat the upper edge of the film bag. If the transverse sealed seam of thestrip is not damaged, it is thusly ensured that the film bag has notbeen opened.

Within the context of the invention is that before the filling of thebag the profiled strip is connected only to the front face over itsentire length and extends into the region of the side folds. In thisembodiment the bag can be completely open at it upper side for filling.An alternative embodiment provides that the profiled strip connected tothe front face is placed over the side folds and is connected with thesebefore a filling of the bag. In this embodiment, the bag filling openingis somewhat smaller

The subject matter of the invention is also a method for manufacturingthe described film bag. The method according to the invention comprisesthe following method steps:

-   -   a) slide punch-outs are applied to a flat foil web;    -   b) resealable closures consisting of two profiled strips which        rest one on the other and connected to each other as well as a        slide which overlaps the sealed edges of the profiled strips in        a rider-like manner are placed on the planar film web        transversely to the direction of the web in such a way that the        slides lie inside the slide punch-outs, and are joined to the        film web at the ends;    -   c) subsequently the film web is guided through folding stations        in which the film web is folded and the side folds are formed;    -   d) the film layers of the film web which rest one on the other        are connected by sealed seams, wherein with transverse sealed        seams the bottom of the bags are formed transverse to the        direction of the web and the resealable closures are connected        with a front face of the bags and wherein along the side folds        longitudinal sealed seams are applied in the longitudinal        direction of the web which extend from the bottom to the upper        edge of the bag;    -   e) bags are separated from the bag run formed in the method step        d)

The invention is based on the consideration of applying resealableclosures on the planar film web before the film web runs through thefolding stations in which it is folded and the side folds are formed.The application of the resealable closures according to the inventioncan be integrated in present bag manufacturing systems. The methodaccording to the invention makes use of punching means and foldingapparatus already present. Thereby the technical problem has to besolved, however, that the resealable closures can shift during thetransport of film web through the system, in particular, in the foldingapparatus since the resealable closures at first are only connected tothe film web at their ends. An opening has to remain between theprofiled strips of the resealable closures and the film web so that thebag can be filled at the top end. Only after the bag is filled is thisopening closed by the sealing of the profiled strips to the front faceof the film bag. The technical problem described is solved according tothe invention through method step b). In accordance with the invention,slide punch-outs are introduced which lie exactly at the position of theslide and prevent a shifting of the resealable closures and the slideagainst the run direction of the film during the run of the web throughthe bag production system, in particular, also during the run of the webover the guiding trays of the folding stations. The slides are fixed tosome extent in the associated slide punch-outs. The slide punch-outs areround holes in the simplest case whose diameter is adapted to thegeometry of the slide.

According to a preferred embodiment of the invention, in zones of theplanar film web from which the side folds are formed window-shapedopenings are punched which define the upper end of the side folds of thebag. Advantageously, perforation lines are punched in further in theplanar film web transverse to the longitudinal direction of the webwhich are arranged at the level of the window-shaped openings and in thebag run respectively define a strip-shaped section projecting over theslide of the resealable closures up to the bottom sealed seam of theadjacent bag. The strip can be used as an originality seal. Before thefirst use of a bag, the strip is torn off in whereby the slide of theresealable closure is exposed. The window-shaped openings as well as theperforation lines are introduced in the planar film web before this runsthrough the folding stations in which it is folded and the side foldsare formed. In this connection, the technical problem exists that thefilm web can tear in the folding stations at the perforation lines andat the window-shaped openings can tear when the forming tools engage inthe perforation or in punch-outs and the film web catches on the tools.This problem can be solved in a surprisingly simple manner in that theperforation lines extend substantially over the web width, however, withthe provision that between the perforation and the window-shapedopenings, respectively, a 5 mm to 50 mm wide, non-perforated film arearemains. The film web is guided in the folding stations such that theedges of the folding tools do not abut against the non-perforated filmregions between the perforation and the window-shaped openings. Thefolding over of the film web to a tubular web takes place by usingtriangular folding trays. When the window-shaped openings are guidedconcentrically over the triangular trays, surprisingly they do not catchon the trays.

Subsequently, punching cuts can also be introduced in the longitudinalsealed seams which join at the perforation lines.

In the following, the invention will be explained on the basis of adrawing illustrating only one embodiment. The figures showschematically:

FIG. 1 a flattened film bag,

FIG. 2 shows the film bag in FIG. 1 after its filling,

FIG. 3 shows a method for producing the flatten film bag illustrated inFIG. 1,

FIG. 4 shows a flat film web with the punch-outs according to theinvention introduced before the film web runs through the foldingstations and the sealing stations.

The film bag illustrated in FIG. 1 has two front faces 1, 1′, side folds2 which are inserted between the front faces in a V-shaped manner and aresealable closure 3 in a top opening in the bag. The resealable closure3 comprises two profiled strips 4, 4′ and a slide 5 joining the profiledstrips. One of the profiled strips 4 is connected to a front face 1. Theother profiled strip 4′ can be connected to the other front face 1′after a filling of the bag. The film layers of the bag which rest one ontop of the other are connected by transverse and longitudinal sealedseams at the bottom and along the edges of the side fold 2, wherein thelongitudinal sealed seams 6 run along the side folds 2 extending fromthe bottom to the upper edge of the bag. The resealable closure 3including its slide 5 is arranged at a distance from the upper bag edge7 inside the bag. A front face 1′ of the bag contains a slide punch-out8 matched to the dimension of the slide 5 in which the slide 5 ispositioned before the bag is used for the first time.

The front faces 1, 1′ have a strip-shaped section 9 covering theresealable closure 3 at the upper end of the bag which can be torn offalong a perforation line 10 arranged approximately at the level of theslide 5 or below the slide. Punching lines join at the end ofperforation line 10 which extend through the longitudinal seal seams 6up to the outer edges of the bag. The side folds 2 end below theperforation line 10. The strip-shaped section 9 can be separated alongthe perforation line 10 and the joining punching lines 11 of the filmbag. The resealable closure 3 is thereby exposed.

The film bags represented in FIG. 1 are used, for example, for packaginganimal feed. The filling is carried out at the top of the bag. Thefilling is introduced in an opening which is still present between theresealable closure 3 and a front face 1′ of the film bag. Afterwardsthis opening is sealed by a sealed seam. In addition, the upper edge ofthe strip-shaped section 9 which is torn off at the first use of thefilm bag is sealed as an originality seal. The sealing is carried outwith a transverse sealed seam 12 which connects the film layers. In thebag filling system the bottom of the film bag is folded again to a flatbottom standing bag. FIG. 2 shows the filled flat bottom standing bag.

The method for producing the flattened film bag illustrated in FIG. 1 isrepresented schematically in FIG. 3. In a planar film web 13 slidepunch-outs 8 are introduced. On the film web 13 provided with slidepunch-outs 8, resealable closures 3 consisting of two profiled strips 4,4′ which rest one on the other and connected with one another as well asa slide 5 which overlaps the closure edges of the profiled strips 4, 4′in rider-like manner are placed transverse to the web direction in sucha way that the slide 5 lies in the slide punch-outs 8. The profiledstrips 4, 4′ are connected only at the ends with the film web 13.Subsequently, the film web 13 runs through the folding stations in whichthe film web 13 is folded to a tube and the side folds 2 are formed. Inthe sealing station 15, the film layers which rest one on the other areconnected by sealing seams 6, 16, 16′, in which the bottom of the bagsare formed with transverse sealed seams 16, 16′ transverse to the webdirection and the resealable closures are connected to a front face 1 ofthe bags and wherein along the side folds 2 longitudinal sealed seams 6are applied in the longitudinal direction of the web which extend fromthe bottom up to the upper edge 7 of the bag. In this manner a bag run17 of bags ensues which are connected together at the bottom side,respectively, top side end. The bags are finally separated from the bagrun 17.

It is particularly clear from FIG. 4 that in zones 18 of the planar filmweb 13 from which the side folds 2 are formed, window-shaped openings 19are punched out which define the upper end of the bag side folds. Inaddition, the perforations lines 10 are punched in which are arranged atthe level of the window-shaped openings 19 and in the bag run 17respectively define a transverse strip and/or strip-shaped section 9,which projects over the slide 5 of the resealable closure 3 up to thebottom sealed seam 16 of the adjacent bag. It is inferred from FIG. 4that the perforation line 10 extends over the web width provided thatbetween the ends of the perforation and the window-shaped openings 19,respectively, a 5 mm to 50 mm wide non-perforated film region 20remains. The non-perforated film region 20 between the perforation andthe window-shaped openings 19 prevents that the film web 13 tears in thefolding station 14. In the longitudinal sealed seams 6 punching cutsand/or punching lines 11 are applied which join at the perforation lines10.

In the exemplary embodiment illustrated in FIG. 1, the profiled strip 4connected with the front face 1 is placed over the side folds 2 before afilling of the bag and connected with these. Within the context of theinvention is also that before a filling of the bag the profiled strip 4is connected only with the front face 1 over its entire length andextends up to the area of the side folds 2.

1. A film bag with two front faces (1, 1′), side folds (2) which areinserted between the front faces in a V-shaped manner, and a resealableclosure (3) in a top opening in the bag, comprising two profiled strips(4, 4′) and a slide (5) joining said profile strips, wherein one of saidprofiled strips (4) is connected to a front face (1) and the otherprofiled strip (4′) after a filling of the bag can be connected to saidother front face (1′), wherein the film layers of the bag which rest oneon top of the other are connected to transverse and longitudinal sealedseams at the bottom side and along the edges of said side folds (2) andwherein the longitudinal sealed seams running along said side folds (2)extend from the bottom to the upper edge (7) of the bag, wherein saidresealable closure (3) including its slide (5) is arranged at a distancefrom the upper bag edge (7) inside the bag and that at least one frontface (1′) of said bag contains a punched out area (8) for the slidewhich is matched to the dimensions of said slide (5), in which saidslide (5) is positioned before the use of the bag for the first time. 2.The film bag according to claim 1, wherein said front faces (1, 1′) havea strip-shaped section (9) at the upper end of said bag covering saidresealable closure (3), which can be torn off along a perforation line(10) arranged at the level of said slide (5) or below said slide.
 3. Thefilm bag according to claim 2, wherein punching lines (11) which extendthrough said longitudinal sealed seams (6) to the outer edges of saidbag join at the ends of said perforation lines (10).
 4. The film bagaccording to claim 2, wherein said side folds (2) end below saidperforation line (10).
 5. The film bag according to claim 1, whereinsaid profiled strip (4) connected to said front face (1) before afilling of the bag is connected on its entire length only to said frontface (1) and extends into the region of said side folds (2).
 6. The filmbag according to claim 1, wherein said profiled strip (4) connected tosaid front face (1) is placed over said side folds (2) and connectedwith these before a filling of a bag.
 7. The method for producing filmbags according to claim 1, comprising the following method steps: a) ina planar film web (13) slide punch outs (8) are introduced; b)resealable closures (3) consisting of two profiled strips (4, 4′)resting one on the other and connected to each other as well as a slide(5), which overlaps the sealing edges of said profiled strips (4, 4′) ina rider-like manner, are disposed transverse to the web direction suchon the planer film web (13) that the slide (5) lie in said slidepunch-outs (8), and are connected at the ends to said film web (13); c)said film web (13) is guided through folding stations (14) in which saidfilm web (13) is folded and side folds (2) are formed; d) the filmlayers which rest one on the other are connected by sealed seams (6, 16,16′), wherein the bottom of the bags formed with transverse sealed seams(16, 16′) transverse to the web direction and said resealable closures(3) are connected with a front face (1) of the bags and wherein alongsaid side folds (2) longitudinal sealed seams (6) are applied in thelongitudinal direction of the web, which extend from the bottom to theupper edge (7) of the bags; e) bags are separated from the bag run (17)formed in the method step d).
 8. The method according to claim 7,wherein window-shaped openings (19) which define the upper end of saidbag folds (2) are punched out in zones (18) of said planar film web (13)from which said side folds (2) are formed.
 9. The method according toclaim 8, wherein in said film web (13) transverse to the longitudinaldirection of the web, perforation lines (10) are punched which arearranged at the level of said window-shaped openings (19) and whichdefine in said bag run (17), respectively, a strip-shaped section (9)which projects over said slide (5) of said resealable closure (3) up tosaid bottom sealed seam (16′) of the adjacent bag, wherein saidperforation lines extend over the width of the web provided that a 5 mmto 50 mm wide, non-perforated fim region (20) remains, respectively,between the perforation and said window-shaped openings.
 10. The methodaccording to claim 9, wherein in the londitudinal sealed seams (6)punched cuts (11) are introduced which join at said perforation line(10).